You might take a look at Usenetserver - I've been with them for years
and they have evolved into a good provider at a low cost. I pay
$39.95 for 3 months unlimited use. The retention on the server is now
better than 90 days.

You may try this site, it is a listing of free usenet servers you may check out.
Haven't had time myself to check out, but free is free

Snider.... you for got the link.................

http://teranews.com

I paid $3.95 one-time sign-up fee and been using it for several years.